This invention relates to locking mechanisms. More particularly, this invention relates to locking mechanisms which incorporate a floating roller locking member.
Locks which include a locking member/locked member assembly commonly alternately and selectively restrain and release a load force applied to the assembly. Such assemblies are known to utilize the restrained load as a motive force in the mechanical operation of the locking mechanism itself. For example, where an intruder presses upon a security door which is latched by a dead bolt, the dead bolt desirably remains extended in its locked position. Pressure applied by the intruder tends to frictionally press the bolt against the door jamb, desirably preventing the bolt from being withdrawn while load forces are applied. Alternately, locked member/locking member assemblies may be configured to harness a load force restrained by the lock for moving the locking member from a locked position to an unlocked position. A rotatable bow string nut of a crossbow is an ancient example of such locked member/locking member assembly.
A drawback or deficiency common to locked member/locking member assemblies which are adapted for utilizing a restrained load force in the mechanical operation of the lock, is that such assemblies are commonly incapable of utilizing such force for both locking and unlocking the lock mechanism.
The instant inventive lock solves or ameliorates the deficiencies noted above by providing structure which allows load forces applied to a member locked by a roller to alternately and selectively hold the roller in its locked position, and drive the roller to its unlocked position.
The locked member of instant inventive lock comprises, for example, a rotatably mounted wheel or a fixedly mounted circular stator. The exemplary wheel or stator has at least a first concavity or indentation extending inwardly from one of its annular surfaces. Preferably, the surface into which the at least first concavity extends is an annular outer surface. Suitably, an annular side wall surface or inner surface of the exemplary wheel or stator may include the at least first concavity. Preferably, the annular surface into which extends the at least first concavity further includes either a plurality or a multiplicity of nearly identical concavities arranged radially around such annular surface. Suitably, the locked member may comprise a straight bar, a curved bar, flat plate, a curved plate, or a chain. Regardless of the geometric character of the locked member, a surface of the locked member necessarily includes such at least a first concavity, and preferably a plurality or multiplicity of nearly identical linearly oriented concavities.
The at least first concavity is preferably fitted for nesting receipt of a locking member, the locking member preferably comprising a roller configured as a spherical body or as a cylindrical body. Where the roller comprises a spherical body, a common ball bearing may be utilized. Where the roller comprises a cylindrical body, a common roller bearing may be utilized. Preferably, the depth of the at least first concavity is less than one-half of the diameter of the roller which it is to nestingly receive. Restricting the depth of the at least first concavity to less than half of the diameter of the roller assures that a wall or edge of such concavity may mechanically outwardly drive the roller, rather than allowing the concavity to capture the roller.
A further structural component of the instant inventive lock comprises a roller stop having a forward end. Preferably, the roller stop and the locked member are movably mounted with respect to each other so that the at least first concavity may move across and in close proximity with the forward end of the roller stop. Such positional arrangement of the at least first concavity and the roller stop assures that a roller which is nestingly received within the at least first concavity will, upon movement of said concavity across the forward end of the roller stop, contact the roller stop. Preferably, the roller stop is mounted in such close proximity with the locked member that, upon such contact of the roller with the roller stop, a side wall or edge of the concavity tends to drive the roller outwardly from the concavity and thence rearwardly from the forward end of the roller stop.
Where the locked member comprises a wheel, the necessary roller stop structure may be advantageously fabricated by drilling or cutting an aperture through a side wall of a housing within which the wheel is rotatably mounted. Where the roller comprises a spherical ball bearing, such aperture preferably has a circular cross section, and where the roller comprises a cylindrical roller bearing, such aperture preferably has a square or rectangular cross section. A side wall of such circular or rectangular channel advantageously functions as the necessary roller stop. Where the locked member comprises a stator, bar, plate, or chain, the roller stop may similarly be configured as a channel extending through a side wall of a housing adapted for receiving and accommodating lateral sliding motion of such locked member. While the roller stop preferably comprises a side wall of such drilled or cut channel as described above, numerous other roller stopping means, including ball stopping pins, ridges, and flanges, may be suitably utilized.
A plunger mounted for reciprocating forward and rearward movement with respect to the locked member is necessarily provided. While the plunger occupies its forward position, a forward end of the plunger drives the roller to a forwardly extended position wherein the roller is nestingly received within one of the concavities of the locked member, and wherein a side wall of the roller overlies the forward end of the roller stop. With the locked member, the concavity, the roller, the roller stop, and the plunger so positioned, load forces applied to the locked member tend to simultaneously drive the roller outwardly from the concavity, and into and against the roller stop and the forward end of the plunger. Resistance to rearward motion of the plunger at that instant tends to bind the roller in place between triangularly arranged contact points upon the wall or edge of the concavity, the roller stop, and the forward end of the plunger. Such binding effect causes the roller to resist movement of the concavity past the roller stop. Such resistance to movement of the concavity effectively locks the locked member in place with respect to the roller stop.
Upon release of the plunger for rearward motion and upon application of a loading force to the locked member, the locked member""s concavity commences movement across the forward end of the roller stop, driving the roller out of the concavity, and thence rearwardly across the roller stop toward the plunger, releasing and unlocking the locked member.
A second housing configured as a tube whose bore is closely fitted for sliding receipt of the plunger comprises a preferred structure for accommodating the necessary reciprocating movement of the plunger. Where the roller stop comprises the preferred channel extending through a wall of the first housing, as described above, a forward end of such tube containing the plunger is preferably fixedly mounted upon an outer wall of such first housing in alignment with such channel. While such second housing comprises a preferred means for facilitating reciprocating motion of the plunger, numerous other structures such as slide ridge and slide channel combinations, slide rails, slide tracks, or slide frames may be utilized.
The reciprocating forward and rearward motion of the plunger is necessarily controlled by a toggle which spans between a rearward end of the plunger and a point rearward of the plunger, which point is preferably mechanically fixed in relation to the roller stop. Preferably, the conjunction of the rearward end of the toggle and said mechanically fixed point comprises a pivot joint, and preferably the medial joint of the toggle and the toggle""s forward connection to the plunger similarly comprise pivot joints. Upon flexion of the toggle, the plunger moves rearwardly, unlocking the locked mechanism, and upon extension of the toggle, the plunger moves forwardly, driving the roller forwardly, locking the lock mechanism as described above.
The toggle is necessarily capable of slight hyperextension which is resisted by an hyperextension stop, the hyperextending motion allowing load forces applied to the locked member to urge the assembly to remain in its forwardly extended and locked position. Where the plunger is reciprocatingly mounted within the preferred second hollow bored or tubular housing, as described above, a rearward end of such housing may be advantageously utilized as support for the preferred pivot mount of the rearward end of the toggle. Where such configuration is utilized, an inner surface of a side wall of such housing further advantageously serves as the hyperextension stop.
Flexion and extension means adapted for alternately and selectively flexing and extending the toggle are preferably provided. A preferred flexion and extension means comprises a lever arm extending rearwardly from a rearward end of the toggle, such lever arm utilizing the preferred rear pivot joint of the toggle as its fulcrum. Manipulation of such preferred lever arm tends to pivot and counter-pivot the rearward link of the toggle, alternately flexing and extending the toggle, and causing the plunger to alternately move forwardly and rearwardly, alternately driving the roller forwardly for locking the locked member, and pulling the plunger rearwardly, releasing the locked member. Suitably, the preferred lever arm may differently extend from the rearward link of the toggle joint, such lever arm continuing to utilize the rearward pivot of such link as its fulcrum. Numerous other flexion and extension means applicable to the toggle joint may be utilized. For example, an actuator cable operatively connected to the toggle at a point between the toggle""s forward and rearward pivots may be utilized. As a further example, one of the toggle""s links or legs may be fixedly attached to a pivoting pin or axle, and rotational torque may be applied to such pin or axle.
Accordingly, it is an object of the present invention to provide a locking mechanism adapted for selectively and alternately securing and releasing locked members including wheels, stators, bars, plates, and chains.
It is a further object of the present invention to provide such a mechanism further incorporating a roller configured as a cylinder or as a sphere, as a locking member.
It is a further object of the present invention to provide such a mechanism which is capable of utilizing load forces applied to the locked member for driving the locking member to an unlocked position, and, alternately for securing the locking member in its locked position.
Other and further objects, benefits, and advantages of the present invention will become known to those skilled in the art upon review of the Detailed Description which follows, and upon review of the appended drawings.